Calculating remediated vulnerabilities

[tvm_analyst]

I have 2 fact tables containing vulnerability data, a finding table and a finding_date table.  The finding table is overwritten with the current findings after scans are run, the finding_date table is appended with the same data.  Vulnerabilities found in the finding_date table that are not in the current finding table can be considered remediated. I created a unique_key column by combining the asset_id + vulnerability_id.  For each unique_key, the remediation_date would be the LASTDATE() + 1 for all unique_keys that are not found in the finding table.

What I would like to do is create a calculated table from these 2 tables with the following columns: asset_id, vulnerability_id, (or unique_key), first_found_date, vulnerability_instances, remediation_date (if available).  I can then add calculated columns for measuring SLA's and vulnerability status.